Methods for wound protection and therapy

ABSTRACT

Method and apparatus for protecting and treating wounds are provided. A housing is adapted to be adhesively secured over the wound of an injured or infected person. The housing has an opening for access to the wound, and is further provided with inlet and outlet ports for the application of therapeutic materials. There is particularly provided a program for a closed looped system for such wound care. Additionally, the invention provides for a protective and treating cover for the eye, which can be either opaque or translucent. Additionally, a mechanism for accurately depositing eye drops without risking injury to the eye is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of co-pending U.S.patent application Ser. No. 11/122,863 filed 4 May 2005, which is herebyincorporated by reference in its entirety herein.

TECHNICAL FIELD

This invention relates to protective dressing and cover for an injuredbody part, such as the eye, as well as methods and devices forsimplifying general wound care, delivering medication thereupon andaccelerating healing by creating an optimal microenvironment using arange of therapeutic modalities.

BACKGROUND ART

With improving medical technologies, and a growing as well as agingworld population, both the number of surgical operations and theircomplexity increase. Take just the eye, for example, millions moreelderly patients each year undergo various ophthalmic surgeriesincluding cataract extraction, intraocular lens replacement, cosmeticblepharoplasty, entropion, ectropion and tear duct repair. Youngerpatients also increasingly seek LASIK correction of myopia andastigmatism. More infants also undergo strabismus or amblyopia(lazy-eye) correction. As a result, many tens of millions of eyesurgeries occur each year following which the operated eye needs to beprotected in the weeks following eye surgery from pressure injury andreceive liquid topical medications several times daily. This isespecially critical following “open globe” operations (such as cataractsurgery, because accidental pressure can lead to rupture of the globe,and partial or total loss of vision). Similarly, following accidentalinjury to the eye (from foreign body to chemical splashes) the injuredeye is typically covered and protected for a period of time withmultiple daily administration of topical medication.

All of the above post-operative or post-trauma care of the eye currentlyrequires an uncomfortable rigid metal or plastic discoid fenestrated eyeshield to be taped in place over the periorbital area. The disc is ovoidin shape and measures 1 mm to 3 mm thick, depending on material. Thediscoid shield and the adhesive tape holding it in place must be removedmultiple times each day for medication administration. The edge of theeye shield compresses uncomfortably against the bony prominencesunderlying the eyebrow and cheek, and the absence of a seal between theshield and the skin precludes taking a shower or simple washing of thehead or face. The fenestration of the discoid shield is to diminish theamount of light coming into the photosensitive eye, or to allow thepatient to see, depending on the personal circumstance of the patient.

Even more annoying, and uncomfortable to the point of pain, is thepeeling back of the tape holding the eye shield to administer medicationseveral times a day. This tedious and unpleasant process is aggravatedby the discomfort of peeling adhesive tape off eyebrows and sensitivefacial skin. Elderly patients are especially susceptible to theassociated problems and complications because they have thin atrophicskin and brittle capillaries that bruise easily, their vision is alreadyimpaired and they often do not have skilled live-in help to assist withproperly dressing the eye and administering the medication multipletimes each day. This situation threatens patient compliance, and boththe quality of post-operative eye care and surgical outcome. Therepeated peeling of adhesive tape removes the buffering layer of deadsquamous cells and brings fresh adhesive into proximate contact withmicrocapillaries, t-cells and histiocytes. This incites tissueirritation or allergic reaction to the tape adhesive. Lastly, the eyeshield and associated tape is visually unattractive and draws unwantedattention from on-lookers.

Also difficult is the precise delivery of liquid eye medication tooneself. It is difficult to judge:

1) when the medicine dropper is positioned properly over the eye (suchthat the medication does not land outside of the eye margins and theexpensive medication is wasted), or

2) when the tip of the eye drop dispenser is too close to the eye (whichwould risk contamination of the dispenser tip and risk abrasion injuryto the cornea).

A variety of other eye patches are disclosed in prior teachings, mostcomprising of soft padded ovoid patches, some with an inflatable bladderor intermediate pocket for inserting extra padding or compress. Theseprior art all require changing with each medication delivery, do notprotect the eye from water (as while taking a shower), and with theexception of the hard discoid shield, do not protect the injured eyeagainst external pressure.

Turning attention now to examples of other types of wounds, thisinvention further pertains to 1) contaminated wounds, 2) chronicdecubitus wounds and 3) wounds from plastic and reconstructive surgery.

The cornerstone to wound management is maintaining a clean, sterile andoptimized environment for healing, including good oxygenation, nutritionand vascular flow. Many wounds are “dirty” from traumatic injury or frominfection superimposed on underlying disease processes (such as diabeticperipheral vasculopathy, other co-morbidities or malnutrition) thatrenders the body incapable of dealing with the extent of tissuecompromise and growing microbial load.

In a blast injury, as might be sustained by a soldier, an enormous loadof soil organisms is forced deep into tissue, which then feeds andmultiplies on the extensively damaged tissue. This is a very challengingcategory of wounds to clean and heal. Perhaps the most challenging woundof all is the chronic decubitus wound because the underlying vascularitythat determines tissue viability is often substantially compromised.Wounds from plastic and reconstructive surgery may entail skin grafts ortissue pedicles that have tenuous vascularity, must be protected fromoutside shear force (unintended movement upon the graft tissue, such asduring dressing change) and need an optimum, highly protectedenvironment for healing.

Wound closure involves the migration of epithelial and subcutaneoustissue from the wound periphery toward the center. A good blood supply,aided by the normal activation of a variety of immune system cells isimportant to the healing process. However, the larger or more infectedthe wound is, the greater is the disruption of the original bloodsupply. This translates to a greater degree of local edema, microstasis,hypoxia and hypoperfusion; all increasing the likelihood of wounddeterioration and infection.

Whenever the wound is not clean, wound debridement is an essentialprecursor to wound closure. It is the removal of necrotic tissue,exudate, and metabolic waste from a wound and improves the healingprocess. It reduces the bio-burden of the wound; controls andpotentially prevents wound infection, especially in deterioratingwounds; and allows the physician to visualize the wound walls and baseto assess viable tissue. Exudate usually results from infection.Staphylococcus aureus, for example, is known to produce a fibrin-richbiofilm that is resistant to the body's natural immune response toforeign bodies. Residual necrotic tissue not only impedes wound healing,but can also result in generalized infection, osteomyelitis, septicemia,loss of limb, or even death. Removing the necrotic tissue will helprestore circulation and oxygen delivery to the wound, both critical tohealing. Wounds at sites of rich blood supply, such as the scalp, healfaster and are less prone to infection. Oxygen is required forenergy-dependent metabolic processes, production of free radicals thatkill bacteria, and proliferation of cells, such as fibroblasts andepithelial cells, which are crucial for wound healing. Bacterialovergrowth under hypoxic conditions may compete with the healing tissuefor nutrients and produce exotoxins and endotoxins that could damagenewly generated and mature cells.

Hypoxic conditions in dirty wounds also encourage anaerobic bacterialgrowth which is serious, potentially life-threatening and difficult totreat. Hyperbaric oxygen chambers are available in certain tertiarymedical centers and therapy time is limited to a few hours due to oxygentoxicity. Medical problems commonly treated with hyperbaric oxygentherapy include non-healing wounds, osteoradionecrosis, acute carbonmonoxide poisoning, acute gas embolism, burns, and certain infections.Yet, medical use of hyperbaric oxygen must be applied conservativelybecause of the potential risk of toxicity to the central nervous system(seizure) and lungs. These problems and resource scarcity belie theenormous cost of proper wound care: $20 billion annually in the US justfor chronic wound care in nursing homes. An estimated 1.2 million peoplewith diabetes suffer from lower extremity ulcers each year, and of allthe foot amputations in the United States, 84 percent, or 60,000amputations, are related to diabetic foot ulcers. Proper and timelywound care can significantly reduce the incidence of such tragicoutcome. The teachings of this invention will help curtail the costs andcomplications of wound care.

Debridement may also be required to prepare the wound bed prior toapplication of new biomaterials used to treat chronic wounds, such ascultured keratinocytes and a bioengineered human skin equivalent. Asthese modalities are used more extensively in clinical practice,selecting the appropriate debridement option will become more critical.

Because necrotic and devitalized tissue range from moist, yellow, green,or gray tenacious plaques to thick, leathery black eschar if the wounddehydrates, its removal can pose a challenge. In addition to posing abarrier to oxygen and nutrients, it can also serve as a breeding groundfor microbes, and may mask underlying buildup of fluid or abscesses.

Several types of debridement are available. Mechanical methods includewet and dry dressings, whirlpool, and pulsed lavage. It is laborintensive, may be painful and nonselective because it does notdiscriminate between viable and nonviable tissue. Newly formedepithelium can also be removed by these methods.

Chemical debridement methods, including topical use of enzymatic gelsand solutions can dissolve necrotic tissue from the wound. Various typesof enzymes target specific components of dead tissue, such as fibrin andcollagen. Enzymes that act on necrotic tissue are categorized asproteolytics, fibrinolytics, and collagenases. Enzymes for wounddebridement are mostly formulated as ointments, solutions absorbed by awet gauze, hydrocolloids, or hydrogels. The efficacy depends on theenzyme employed, with fibrinolysin ointment regarded as ineffective,collagenase ointment somewhat effective, and papain-urea ointment mosteffective. Because the interface or contact between the enzymaticdressing and necrotic substrate has to be manually changed andrefreshed, a prolonged time is required for these treatments to deliversignificant improvement. This ranges from four days to three weeks withdaily wound treatments for fresh ointment supply (especially during thefirst week).

A laboratory study on rabbits and mice by Yaakobi et al and published inJuly in Wounds 16(6):201-205, 2004, reported that by continuouslydripping proteolytic enzyme solutions such as bromelain, collagenase,papain, pepsin, protease and trypsin in suitable medium, they were ableto vastly shorten the debridement time. The authors concluded, “Thefeasibility of this approach was demonstrated on lab animals by studieson skin treatment and wound debridement. Our results have clearlydemonstrated technical feasibility and efficacy of streaming of enzymesolution. The time required for effective treatment was on a scale of afew hours, substantially shorter than the several days/weeks requiredfor treatment with enzyme-containing ointments. The authors, however,gave no suggestions how to bring this laboratory finding to clinicalapplication, and to contain the continuous enzyme solution run-off ifapplied at the bedside in a clinical setting.

Lastly, biological methods of wound debridement including maggots of theblowfly, Phaenicia sericat, and certain leeches have also been shown tobe effective in debriding certain types of wounds. However, confiningthem within the wound site can pose a challenge and when they wanderoutside the wound onto adjacent normal skin, a creepy-crawly sensationis unpleasant for the patient. It is therefore also an aspect of thisinvention to provide methods wherein such creatures can be easilyconfined in a closed space and their distracting sensation upon thepatient minimized.

Recent advances in general wound therapies have included the applicationof continuous suction to the underside of a wound dressing. It isbelieved that such treatment helps to reduce tissue edema, enhancedrainage and fibroblast cell migration. While negative pressure appearsto accomplish the above, the advanced wound chamber system disclosedherein will provide a yet more advanced system of wound care and therapyas never before available. This includes automated cycles of enzymaticdebridement, wound lavage, irrigation with antimicrobials and immunemodulators, optimization of microenvironment with the infusion ofhigh-concentration oxygen, nitric oxide, cyclical application ofpositive and negative pressure to simulate physiologic circulation andaccelerate wound healing. These methods, devices and special featureswill be disclosed in detail below.

SUMMARY OF THE INVENTION

Given the aforedescribed current state of the art, it is an aspect ofthis invention to provide an effective and yet economical device thatwould simplify and enhance wound treatment by means of a direct-viewinspection chamber that encloses and protects a wound and maintainsaround it certain beneficial microenvironments that heretofore have beendifficult or impossible to attain.

It is also an aspect of this invention to provide a method of wound carethat would sharply reduce the attention and effort needed for wounddressing changes, and accelerate the healing schedule by enabling novelmethods of therapy, delivered with ease and precision at the appropriatetime.

It is another aspect of this invention to provide a method of wound carethat provides for modular compartments with interchangeable andengageable parts to customize for a patient's specific needs.

It is another aspect of this invention to provide a method and devicefor eye care that enables accurate dispensing of eye drops into the eye

It is another aspect of this invention to provide a method and devicefor wound care that reduces the frequency of dressing changes andreduces the incidence of tape irritation reaction and tissue macerationthrough the application of a layer of cyanoacrylate to the skinsurrounding the wound.

It is an aspect of this invention to provide a method and device forwound care through the application of a layer of cyanoacrylate outsidethe immediate wound area to generally confine biological debridementagents within the wound, and discourage their migration beyond theperiphery of the wound and further diminish unpleasant patient sensationassociated with the agents crawling over normal skin.

It is another aspect of this invention to provide a method of wound careto enables infusion of therapeutic fluids such as oxygen, vasodilatorssuch as nitric oxide, proteolytic enzymatic lavages or antimicrobialsolutions, pro-epithelial factors and other growth or healingmodulators.

It is another aspect of this invention to provide a programmable devicethat automatically carries out prescribed customized regimens of woundcare that include beneficial infusions, lavages, heating, cooling andother therapeutic fluids such as oxygen, vasodilators such as nitricoxide, proteolytic enzymatic soaks, antimicrobial solutions,pro-epithelial growth and healing factors and modulators.

It is an aspect of this invention to provide a method/device of woundcare that eliminates dressing and dressing changes, allows directvisualization and inspection of wound, relieves focal pressure on thewound and provides programmable optimized milieu for the wound throughthe delivery of beneficial therapies.

It is an aspect of this invention to provide a method/device of woundcare that provides for cyclical application of positive pressure oxygenalternating with negative pressure to improve the circulation anddrainage to the wound area.

BRIEF DESCRIPTION OF DRAWINGS

For a complete understanding of the objects, techniques and structure ofthe invention, reference should be made to the following detaileddescription and accompanying drawings wherein:

FIG. 1 shows an individual wearing the current-art compression-resistanteye dressing over his right eye compared to a compression resistant eyedressing chamber over his left eye as disclosed herein;

FIG. 2 is a perspective view of a typical eye dropper bottle showing astandard collar and neck;

FIG. 3 is a perspective view of an eye-dropper dome designed to aidprecision delivery of eye drops;

FIG. 4 is a cross sectional view of FIG. 3 taken along line 4-4 showingthe shroud locked between the collar and neck of the bottle anddispensing an eye drop over the center of the eye;

FIG. 5A is a detailed perspective view of a compression resistant eyedressing chamber showing the lid open from its base;

FIG. 5B is an enlarged perspective view of a ratchet locking mechanismof FIG. 5A;

FIG. 5C is an enlarged perspective view of a locking tab mechanism ofFIG. 5A;

FIG. 6 is a cross sectional view of FIG. 5A taken along line 6-6 showinga polymer rim base over a foam strip with an underlying layer ofadhesive;

FIG. 7 is a cross sectional view of FIG. 5A taken along line 7-7 showingthe dressing chamber cover with interlocking circumferential ridge;

FIG. 8A is a perspective view of an advanced wound care chamber adaptedto receive various fluids and medicaments;

FIG. 8B is a partial sectional view of an ampoule employed in exerciseof the invention;

FIG. 8C is a cross sectional view of the ampoule of the invention asshown in FIG. 8B, taken along the line 8C-8C;

FIG. 9 is a cross sectional view of FIG. 8A taken along the line 9-9showing one adaptation of the cover to retain intra-chamber adjuncttherapies such as a warm compress;

FIG. 10 is a perspective diagram showing yet another embodiment of thewound chamber system as it applies to treating decubiti of the foot; and

FIG. 11 is a block diagram showing an example of a particularimplementation of a programmable wound therapy device designed todeliver a sophisticated regimen of therapies to optimize wound milieuand accelerate healing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT FOR CARRYING OUT THEINVENTION

FIG. 1 shows an individual wearing two types of compression-resistanteye dressing. Over the right eye is the standard currently availabledressing 10 comprising a rigid aluminum or plastic disc 12 with multiplefenestrations. Pieces of adhesive tape 14 are used to hold the disc inplace and must be removed each time eye medication needs to bedelivered, typically three to four times each day. Once the adhesivetape is pulled off, it does not stick again adequately and typically hasto be replaced after each use. Over the course of a 7 to 10-day therapyperiod, the removal and reapplication of the tape 20 to 40 times resultsin considerable skin irritation and adhesive residue build-up.Furthermore, the current eye dressing does not protect the eye againstwetness and does not allow the patient to shower or shampoo the hairduring the course of treatment.

Over the left eye is shown one embodiment of this invention in the formof an eye dressing chamber 20. A lid or cover 22 that can be clear or ofvariable tint and opacity covers a form fitting conforming base ringwhich is adhesive mounted to enclose the entire periorbital area. Thelens can open and close via locking means 26 and is attachable to thebase ring via a hinge mechanism 24. Further construction detail isprovided in FIGS. 5A though 7.

FIG. 2 is a perspective view of a typical eye dropper bottle 30 showinga standard collar 34 and a neck 36 between the collar and bottle. A cap32 keeps the tip of the bottle clean. Unfortunately, it is an impreciseand difficult task for a person to administer eye drops to oneself.Oftentimes, the tip is not properly centered over the eye, so theexpensive medication is wasted. At other times, only a portion of thedrops lands within the eye resulting in an inadequate dose. If thepatient recognizes that less than the full dose is received, he mayattempt to remedicate again, hoping to deliver a full drop to the eyethe second time. This is not a significant problem for antimicrobialdrops; however, many eye drops, especially those for the treatment ofglaucoma are vasoactive and can lead to pressure drop and other untowardeffects. At other times, the tip of the dropper can come too close andactually contact the eye, causing the tip and bottle content to becomecontaminated; worse yet, it can also cause a corneal abrasion. A simpleto use device is needed to help reliably deliver medication drops to theeye.

FIG. 3 is a perspective view of an eye-dropper dome 40 designed to aidprecision delivery of eye drops. Its general shape substantiallyresembles a tall entree serving cover or truncated dome. At the wide endis a smooth and thickened lower rim 46 to prevent any scratch injury tothe eye, and at the narrow end is an opening 48, sized to fit the neck36 of eye dropper bottles. Short slits 44 emanate from opening 48 anddivide the immediate perimeter area into locking tabs that yield toexpansive pressure. In actual use, this dome is inserted, upside downwith smaller opening first, over a capped eye-dropper bottle. Thelocking tabs will yield over the bottle collar 34 and lock around theneck 36 of the bottle.

FIG. 4 is a cross sectional view of FIG. 3 taken along line 4-4 showingthe eye dropper dome locked between the collar and neck of an eyedropper bottle and dispensing an eye drop precisely over the pupil 50 ofthe eye. Note that the dome's wide opening easily encloses the upper andlower eyelashes 49 a and 49 b and should generally be around 25 to 30 mmin diameter. The height of the dome is such that while engaged with theneck of the bottle, the tip of the bottle will not come into contactwith the eyelashes, typically 30 mm or more in height. To use thedome-equipped eye dropper bottle, the patient simply uncaps the bottleand engages the rim 46 of the dome against the bridge of the nose andthe supraorbital margin, an easy-to-find bony prominence immediatelybelow the eyebrow 48. With the patient's head fully tilted back (or withpatient lying supine), this automatically positions the tip of thedropper substantially over the center of the pupil. Even allowing forindividual and racial feature differences, the bottle tip will stillreliably deliver the medication drops well within the eye opening, thusaccomplishing the goal of dispensing eye drops to the eye.

FIG. 5A is a detailed perspective view of a compression resistant eyedressing chamber 20 showing the cover 22 open fully from its base ring21. The base ring is made of a flexible and conformable polymer that ismoldable to fit over slight variations in facial contour. In addition topremolding the cover and base ring in mating shapes that substantiallyconforms to the normal contours of the periorbital region, an optionalmetal strip 27 (FIG. 6) can be molded within the base ring to aid infurther shape adjustment and shape retention. On the underside of thebase ring is a ring of suitably thick foam material 28 that further aidsto cushion and seal the base ring against the periorbital contour.Beneath the foam ring is a layer of adhesive 29 for affixing the basering and its attachments over the eye. Alternatives to using a foam ringto seal the wound chamber against the skin include the use of aminiature inflatable vinyl cushion of the type commonly found ondisposable anesthesia masks. An adhesive ring affixes the cushion to theperiorbital area.

In this illustrated embodiment, the cover 22 of the eye wound chamber isattached to the base ring via a living hinge 24 similar to the typefound commonly on toothpaste caps and shampoo bottles. The hingeprovides a tendency to remain in either the open or closed positions,the first tendency is useful during direct examination by the physicianor for medication dispensing. The cover is secured to the base ring atthe opposing end by any of a number of latching means. FIG. 5B shows theenlargement of one push-away ratchet-type locking tab mechanism 26 a onthe nasal side of the base ring that locks with an interlockingprojection 26 b on the corresponding part of the cover, as shown in FIG.5C. So as not to distract from the main features of this invention,other interlocking and hinge mechanisms for securing the cover to thering base are deliberately not shown; but should be apparent to thoseskilled in the art from this disclosure.

FIGS. 6 and 7 show cross section views of FIG. 5A taken along lines 6-6and 7-7. Surface features that aid in interlocking of the base ring 21with the cover 22 include beveled edges leading to a center groove 25 bthat mate with a perimeter flange 25 a. These features and otherequivalents can be on the base ring or on the cover, as long as they actin concert to seal out unwanted elements such as water during a shower,or pollen and dust. Other sealing means including O-rings andcompressible flanges are also evident. Detachable attaching meansaccommodate easy switching of the cover from clear to opaque, fromventilated to water-tight types, as may be dictated by the patient/Eschanging needs. The eye wound chamber can be made in fashionable shapesand colors and can be made in tandem units like a pair of goggles andadditionally be used by city dwellers to protect the eyes from smog orallergy suffers from pollen and other antigens during times of specialneed. Workers can also use them to protect the eyes from dust and fumes.The increasing incidence of ophthalmic allergies from biologicalantigens such as pollen to chemical pollutants through urbanizationincreases the need for a stylish and effective eye shield for everydayuse

When using the eye dropper dome as described in FIGS. 2 and 3 inconjunction with an eye wound chamber, the lower rim 46 of the dome canengage with the base ring or a variety of optional docking structures onthe ring. One example of such a docking structure is an upper perimeterflange that projects anteriorly from the rim of the base ring; or theflange can be entirely circumferential. Such a flange can provideadditional shielding from water entry, as when the patient is taking ashower.

FIG. 8A is a perspective view of a more generalized and advanced woundcare chamber 70 which is shown with a modified cover 22 b in openposition and the lower base ring in the form of a base chamber 21 bsurrounding an open wound 72 of the forearm. The attachment means forthis chamber to the skin can include an adhesive foam strip 28, aspreviously discussed, an adjustable Velcro strap with optional anchors(not shown) on the side wall of base chamber, or any one of a number ofother substitutes as would be apparent to those skilled in the art.

Attachment structures such as retainer posts 78 can optionally be partof the cover 22 to allow items of benefit to be held within the chamberabove the wound 72. This is further discussed under FIG. 9.

The wound chamber can additionally have an optional inlet port 74 andoutlet port 76, adapted to receive infusion lines that may be uni- orbidirectional medical tubing. Again, for clarity's sake, the exactstructures of these ports are not shown but any of a number of suitablemedical ports and coupling mechanisms may be used and substituted. Theseinclude simple compression-fit ports, multi-way stopcocks, luer-lock,and self sealing membrane ports as commonly found in central venouscatheters and other advanced vascular catheters.

The inlet port 74 may be placed anywhere on the lid or base chamber ofthe wound chamber and should generally be in direct proximity to thewound. However, the drainage port 76 should ideally be in the mostdependent portion of the chamber to facilitate drainage. Through theinlet and outlet ports, a circulation of chilled or heated air or oxygenmay be infused depending on the nature and therapeutic needs of thewound. The air or oxygen may further be humidified. Other gases such asnitric oxide, which has vasodilator and cellular signaling properties,can also be used. Instead of needing a hyperbaric chamber, high oxygenconcentration to the wound can easily be attained locally without theattendant cost and toxicity complications. All that is needed is to keepthe wound chamber filled with pure oxygen, a very simple and economicaltask accomplished by infusing the gas from a small reservoir.Additionally, cycles of gentle or pulsatile lavage with saline orproteolytic enzymes can be passed through efficiently using aprogrammable pump system as shown in FIG. 11.

If the chamber 70 is to be used for therapies requiring fluid-tightnessso that the fluids stay within the chamber, the foam should be of theclosed-cell type. The term “fluid-tight” or related terms as used inthis specification means sufficiently leak-resistant to allowinsufflation or vacuum suction to create an intra-chamber pressure thatis above or below ambient pressure, or to substantially retain fluidswithin. Various cyclical patterns of fluid application can be programmedto optimize the wound chamber milieu selected from the following:

1) Application of a local anesthetic

2) Application of a saline lavage with the effluent collected forcentrifuge, cytoanalysis, microbial culture, etc.

3) If wound is contaminated with cellular and/or microbial debris,infusion of proteolytic enzymes such as papain, trypsin, collagenase,Bacillus subtilis protease, vibriolysin, krill protease, chymotrypsin,clastase, dipase, proteinase K, and Clostridium multifunctional protease

4) Application of an antimicrobial

5) Application of wound healing factors and immune modulators

6) Application of oxygen at ambient or above-ambient pressure

7) Application of nitric oxide

8) Application of low suction.

After a dirty wound is cleaned, there is no longer a need to applylavage and proteolytic digestion cycles. At this point, the therapyfocuses on delivery of oxygen and other beneficial fluids and theapplication of a cycle of intermittent positive and negative pressures,lasting one to several minutes per cycle. This simulates the normalvascular flow of the circulatory system at the tissue level.

When positive pressure is applied in the form of pure oxygen, oxygen isdriven into the tissue and capillaries along a favorable gradient andthe interstitial pressure rises pushing cellular edema into lymphaticchannels to decrease the local swelling. Next, the programmable pumpsystem reverses the pressure gradient to slightly negative, creatingsuction that brings fresh blood flow, along with all the inherentbeneficial factors to the wound. This cycle is repeated, with cycles ofother beneficial therapies such as nitric oxide, interposed. For costsaving and portable module size considerations, it may be desirable tofilter effluent gases such as oxygen and nitric oxide and recycle theiruse. In such an arrangement, after several cycles, the gases could becompletely purged and new aliquots of gases introduced.

FIG. 9 is a cross-section view of FIG. 8A taken along lines 9-9. Thisdrawing shows the base chamber 21 b resting on a ring of foam base 28that is adhesively attached to the skin 74 of the wrist. Cover 22 b isshown with a convex contour and retainer posts 78 that allow simpleanchoring of a retainer structure 82 such as a sheet or strip 82.Retainer sheet or strip can have perforations (not shown) which snapover or interlock with retainer pins 78 b that protrude superiorly fromthe retainer posts. Another reverse type of anchoring is shown on theleft side in the cover 22 b of FIG. 8A. Many other equivalents andalternative anchoring methods are well known in the art. The retainersheet or strip can be made of polymer or fabric. Between retainer sheetand cover 22 is created a space 80 which can retain a therapeutic itemsuch as a heating or cooling gel pack, or other treatment modalitiesincluding moxa or moxibustion material, oxygen generator or nitric oxidedonor substances.

The cover element 22 can be interchangeably attached to the base via adetachable hinge or any of a number of disconnectable engagement meansthat are apparent to those skilled in the arts

Turning attention now back to FIG. 8A, it is anticipated that undercertain conditions of therapy wherein the skin surrounding a wound isexposed to prolonged periods or cycles of lavage and enzymatic therapy,maceration of the otherwise uninjured tissue can occur. Furthermore, inwound therapy using maggots and leaches, it is disturbing to the patientto have the creatures crawl beyond the wound boundaries. It is thereforean object of this invention to provide a novel method by which a durablebarrier is provided against liquid penetration and wandering leeches andmaggots. The method and device are hereby disclosed. As shown in FIGS.8B and 8C, an ampoule applicator 140 has a flexible and protectablecylinder 142 of a suitable plastic or polymeric material that receives acrushable ampoule 144 having cyanoacrylate polymer contained therein.One end of the applicator 140 has a sponge applicator pad 146. Prior tothe application of the wound chamber to the skin, the cyanoacrylateampoule 142 is crushed, releasing the liquid to the sponge pad 146. Thecrushing of the ampoule is facilitated by sharp protruding ribs 148interiorly of the cylinder 142. Longitudinal V-shaped grooves 150facilitate collapsing of the cylinder 152 upon the ampoule 144 to effectthe breakage and release of the liquid 154, therein. A pod 152 upon theouter surface of the cylinder 152, and in alignment with the ribs 148directs the proper positioning for the application of crushing force andplacement of the user's thumb or finger.

The applicator pad 146 is used as a paint brush to apply a layer ofcyanoacrylate over all of the surface area that would be covered by thefootprint of the wound chamber except for the wound itself. This layerof cyanoacrylate now provides multiple benefits including:

1) enabling the chamber base to adhere stronger and better;

2) minimize incidence of adhesive sensitivity by providing a durablebarrier;

3) protect skin from maceration secondary to prolonged contact withliquids;

4) discouraging the unwanted migration of maggots and leeches via achemical mat; and

5) dull the disturbing proprioceptive sensations patients experiencewhen the above creatures wander outside of the wound.

An alternative method to preventing skin maceration includes theapplication of a polymer film that attaches to the skin via adhesive onthe underside. The disadvantage of this method is that wound shapes aretypically irregular, so the polymer has to be cut or trimmed to fitaround the wound edge. In contrast, the novel method described usingcyanoacrylate requires only a few seconds of fast painting with a spongeapplicator.

FIG. 10 shows yet another embodiment of the wound care chamber in theform of a wound boot 100. Diabetic decubitus ulcers affecting the toe at102 and the heel at 106 are shown. In this instance it is imperative toimprove the wound milieu by taking the pressure off the ulcers andimmediately instituting an aggressive program of debridement withenzymatic digestion, vasodilation and high oxygenation. A low-pressurecuff 108 has a wide pressure-diffusing inside-cuff 104 extending all theway towards the ankle. This is to diffuse the pressure to the calf andnot further compromise the diminished circulation in a diabetic limb. Aninflation port 104 a may be optionally equipped with a pressure gauge toindicate safe pressure range near or below diastolic. The cuff canoptionally be intermittently deflated and inflated via controlledmechanical means such as a timer controlled valve interposed between anair pressure source and the cuff. Alternatives to the low-pressure aircushion include high quality foam padding

Wound boot 100 is shown with two openable hatches, a front hatch 110 toaccess the toes, and a posterior hatch 112 to access the heel. Thesehatches are reversibly attachable to the main boot via single actionlatches 114 or dual action latches 116 that have mechanisms similar tothose commonly found on ski-boots and tool boxes. Many other attachingand latching means are available and will not be elaborated. One or moreanchoring means 120 such as the loop shown at the toe end, allows theboot to be suspended via ropes 122 for elevation either to improvedrainage or for medical examination. Infusion inlets 74 and outlets 76are positioned to allow optimal fluid flow and drainage. Depending onthe desired application, the boot may need to be of a much thickerconstruction than the wound chamber of FIG. 8A, and may needreinforcement ribs at appropriate areas. These considerations,modifications, substitutions, etc. would readily be apparent to oneskilled in the art.

It should be apparent that similar designs can be made to accommodateand contour to other pressure areas such as the elbow or buttocks, or toaccommodate frequent surgical sites such as the breast. It would beapparent to those skilled in the art that such chambers should generallybe of lowest feasible profile, be pressure diffusing and provide secureanchoring means. Where the wound chamber can provide a source of contactpressure to adjacent tissue such as the contralateral leg, such pressurecan be reduced by placing a soft sponge sock or other padding over thegeneral area of contact.

FIG. 11 is a block diagram which shows an example of a particularimplementation of an automated wound chamber therapy system. Somecomponents shown, such as remote control, may be optional. Although twopumps are shown, more or fewer pumps may be used and which may beunidirectional or bidirectional. One or more pumps may have specialpumping capabilities including pulsatile infusion for lavage.

Audio capabilities include alarms and speech synthesis. Alarms includereservoir low/empty alarm, pressure and temperature malfunction alarm,time elapsed alarm, etc. which may be wirelessly transmitted tocaretaker as an alert. Temperature sensor includes means for heating orcooling the chamber or fluids delivered therein.

This block diagram is to illustrate an example only. The actualimplementation may vary and would be readily apparent to those skilledin the art.

What is claimed is:
 1. A method for treating a wound, comprising thesteps of: securing a housing to skin around a wound using an adhesivelayer that sealingly encloses a perimeter of the housing, the housingdefining a chamber; delivering a therapeutic modality within the chamberto the wound; and controlling the delivering of the therapeutic modalitywithin the chamber to the wound using a programmable device; and whereinthe housing comprises: a base enclosing a perimeter and being open at afirst end and open at a second end; a cushion having an open interior,the cushion secured circumferentially around the first end of the baseto cushion the base upon securement of the housing around said wound bysecurement of the cushion to the skin using the adhesive layer, portionsof the adhesive layer being interposed between the cushion and the skin,the cushion being an inflatable air cushion or a closed cell foamcushion; and a lid attached about the second end of the base to bepositionable between an open position and a closed position, with saidhousing secured about the wound, the chamber and wound are accessiblewhen the lid is positioned in the open position, the chamber is fluidtight when the lid is positioned in the closed position.
 2. The methodof claim 1, wherein the housing further comprises a port to communicatethe therapeutic modality with the chamber.
 3. The method of claim 1,wherein the therapeutic modality is selected from the group consistingof proteolytic enzymes, lavages, nitric oxide, healing factors, immunemodulators, moxibustion, controlled humidity, and controlledtemperature.
 4. The method of claim 1, wherein the therapeutic modalitycomprises cyclical hyperbaric oxygen.
 5. The method of claim 1, whereinthe therapeutic modality comprises cyclical suction.
 6. The method ofclaim 5, further comprising the step of: communicating to theprogrammable device measurements from a sensor monitoring said housing.7. The method of claim 1, wherein the therapeutic modality includesdelivering positive and negative pressures cyclically to the wound. 8.The method of claim 1, wherein the lid is formed of transparent materialfor viewing of the chamber through the lid.
 9. A method for treating awound, comprising the steps of: securing a housing to skin around awound using an adhesive layer that sealingly encloses a perimeter of thehousing, the housing defining a chamber; and delivering a therapeuticmodality within the chamber to the wound, the therapeutic modalitycomprising gas at a pressure that differs from ambient pressure, the gasdirectly contacting the wound; the housing comprising: a base enclosinga perimeter and being open at a first end and open at a second end; acushion having an open interior, the cushion secured around the firstend of the base to cushion the base upon securement of the housingaround said wound, the cushion being an inflatable air cushion or aclosed cell foam cushion, and at least portions of the adhesive layersinterposed between the cushion and the skin; and an openable lidattached about the second end of the base to form the chamber about thewound that is fluid tight when said housing is secured around the wound.10. The method of claim 9, wherein the hosing further comprises a portto communicate the therapeutic modality with the chamber.
 11. The methodof claim 9, wherein the therapeutic modality includes delivering the gascyclically at positive pressure greater than ambient pressure and atnegative pressure less than ambient pressure within the chamber to thewound.
 12. The method of claim 11, wherein the gas within the chamberconsists essentially of oxygen.
 13. The method of claim 9, wherein thetherapeutic modality includes delivering cyclically pressures of nitricoxide within the chamber to the wound.
 14. A method for treating awound, comprising the steps of: enclosing a wound within a chamber thatis fluid-tight by securing a housing to skin around the wound using anadhesive layer that sealingly encloses a perimeter of the housing up theskin, the housing comprising an openable lid; and delivering from asingle source cyclical pressure changes of gas within the chamber to thewound, the cyclical pressure changes include positive pressure greaterthan ambient pressure followed by negative pressure less than ambientpressure.
 15. The method of claim 14, the gas within the chambercomprising air.
 16. The method of claim 14, the gas within the chamberconsists essentially of pure oxygen.
 17. The method of claim 14, furthercomprising the steps of: communicating pressure measurements from asensor monitoring the chamber to a programmable device; and controllingthe delivering of the cyclical pressure changes within the chamber tothe wound by the programmable device using the pressure measurements.18. The method of claim 14, wherein a cushion is secured around thehousing to cushion the housing when the housing is in sealing securementabout the wound, the cushion being an inflatable air cushion or a closedcell foam cushion.
 19. The method of claim 14, the housing beingcompression-resistant.
 20. The method of claim 14, further comprisingthe step of: delivering a therapy selected from the group consisting ofproteolytic enzymes, lavage, nitric oxide, healing factor, immunemodulator, moxibustion, controlled humidity, and controlled temperature.